Siren
by WinterDrake
Summary: Captain Levi's ship is being followed by a creature of the sea.
1. Chapter 1

**Chapter 1**

The captain of the ship, _Wings of Freedom_ , heard the splashing of an unwelcome arrival as he cleaned the railing of his ship. Eren, a young boy of sixteen who dreamt of becoming a captain of his own ship one day, had not cleaned it properly so Levi had decided to redo it himself. He would have the boy do some other extra work as punishment for cleaning so poorly. Eren had likely been daydreaming instead of paying attention to his work again.

Without even looking in the direction of the sound, the black-haired man knew that damned fish-woman was back again. Levi had first seen her some months ago, staring at him from the ocean as he and his men loaded the ship. Since then, Levi had seen her almost a dozen times, speaking with her only twice. Both times to warn her away from his ship. He was sure that she, a creature called a Siren, was following his ship. As her kind were dangerous, Levi had all his men stay on guard. So far only Levi, the ship's doctor Hanje and Eren had seen her. She didn't seem to like to reveal herself when there were many people on deck.

"Why are you back again?" Levi asked sharply before turning to look over the side of his ship. He saw a familiar shade of soaked, ginger hair below him. The man raised his hand to touch the earplugs he kept hanging around his neck on a cord, just to make sure they were there. The captain had his men carry a set or two on them at all times. The Siren looked a little startled that he had figured out she was there so quickly.

"I don't know." The Siren finally spoke as she swam lazily beside his ship, the tops of her bare shoulders peeking out from the water. Her back and tail were also visible as the latter moved up and down in the blue water. Levi could see some sort of drab grey fabric wrapped tightly her torso, which was unusual among her kind. The Siren's tail and scales glittered with a myriad of colors. Her tail was blue but as she moved it, Levi could see flashes red, green, purple and gold as they reflected the sunlight. Her long ginger hair trailed behind her in the water as she swam with the ship.

"Really? It's not because you're trying to catch us off guard?"

"I've told you before. I'm not trying to kill any of you." The Siren sounded exasperated.

"Tch. You think any of us would believe you? I've seen many of your kind drag men into the sea and tear them to pieces." The Captain spat out at the form below him. The ginger-haired creature gave him a look, one that he could almost say was one of remorse. She didn't say anything in response.

Sirens were also called mermaids and they were much different than stories liked to portray. Many naive men, believing those stories thought the naked and beautiful Sirens were harmless. They were not.

A Siren's teeth were much sharper and slightly longer than those of a human. The top half of their bodies resembled human females and they used their nakedness to their advantage. From their elbows grew a fin that was as sharp as a dagger, and just as long. Their hands were tipped with wickedly sharp claws that could tear through flesh. And their songs could drive men mad with lust and lure them to enter the water and their deaths. Siren's were intelligent and bloodthirsty beasts that preyed on humans.

All men and women of the sea carried specially made earplugs to block the sound of a Siren's singing. It was rare to encounter one, but if unprepared, it would mean death. The majority of Sirens Levi had seen were naked but the one that had been following his ship on and off them for the past few months was strangely shy and kept herself covered.

"I wish you would believe me." The Siren muttered, loud enough for Levi to hear.

"Leave. This is your final warning." Levi turned his back on the creature below him. He heard another splash signalling her dive into the water. Levi probably should have had her killed already but this particular one didn't act like the many he had encountered. Most tried to seduce him and his men or sang when they thought they were unprepared. This one just… watched. She was odd and looking like a young woman made Levi hesitate in harming her. It was one of the advantages those beasts had. If they didn't look like innocent women then it would be easier to kill them.

The captain shook himself of his thoughts and went back to cleaning his ship. He hoped the Siren did not come back.

* * *

 _I'm deciding to post this half-finished, older piece I've had sitting around for a year while I try battle writer's block with my other works. I know the mermaid thing has been done to death in almost every fandom but I might as well try it for myself. I apologize to those waiting for updates on my other works!_


	2. Chapter 2

**Chapter 2**

Captain Levi used the _Wings of Freedom_ for a variety of purposes. The ship mainly transported goods from place to place but they also delivered messages and ferried people at times. Levi knew the ocean and its weather well, having been on the water most of his life. His ship was known for being one of the fastest and most reliable for transportation.

Currently, the _Wings of Freedom_ was headed towards Port Sina. They just finished delivering a shipment of spices and been paid fairly well. Levi decided it was alright for his crew to celebrate a little, thanks to all of the success they had been having lately. He could also also admit that he wanted a bit of a break from the ocean as well. A few weeks on land would be welcome.

Hanje and Moblit, the doctor of the ship and and her apprentice, suggested Sina as the location to celebrate. It was the largest and busiest port in the world and there were many places for men and women of the sea to enjoy themselves. Hanje had basically begged and annoyed Levi until he agreed to head to Sina. She was the only crewmember on the ship that could do such a thing and get away with it. This was because Hanje was one of the few people Levi would call his friend and he had known her longer than any other person on the ship.

Eren was a young sixteen year old and the newest member to Levi's crew. He was taken in after he tried to sneak aboard the ship as it was docked to unload a shipment of wine. The boy had easily been found before they set sail. After learning Eren was an orphan and of his dream of becoming a captain of his own ship, Levi decided that Eren would be joining him. He had been impressed by the desire he had seen in brown-haired boy's eyes as he spoke of his dream.

Levi had warned the green-eyed boy that he would be making him work hard but Eren had not cared, smiling widely at being allowed onto ship. He had wanted to be on the ocean so badly. So far, Levi felt the brat was a good worker and leaned quick enough. His cleaning abilities left much to be desired, however.

Oddly, Eren spent a lot of his free time staring out at the ocean from the ship's deck. Levi didn't think much of it, though. It was quite boring on the ship some days so it might have been his way of entertaining himself or passing time.

It was another week before the _Wings of Freedom_ would make it to Port Sina. Until then, Levi kept busy on the ship, trying to keep the thoughts of the strange Siren out of his head.

* * *

"Eren, get the hell away from that thing!" Levi shouted angrily as he saw the boy leaning over the railing. The black-haired man had just stepped onto the deck when he noticed the boy looking into the water and speaking to someone. Eren had something in his hands and was just tossing it at something in the water. Levi already guessed what it was.

The brown-haired boy backed away from the railing and winced when he heard his captain's voice. He knew he was in trouble when older man came rushing over.

"Captain! Uh... Sorry! I was just..." He trailed off, not knowing what to say. Eren couldn't lie very well so he just gave up on trying.

Eren's panicked voice and Levi's sudden appearance startled the creature in the water and she missed catching the food Eren had thrown to her. It dropped into the water and sank. The Siren debated diving out of sight but from the captain's words, he already knew she was there. The female couldn't deny she was curious what he would do this time. He had already given her his 'final warning'. She hoped he wouldn't be too mad at Eren. She had always spoken to him first.

"What the hell are you thinking feeding that thing?' Levi growled as he grabbed the boy by the back of his shirt. The man quickly realized the green-eyed brat was not carrying earplugs around his neck. Narrowing his eyes, he glared at the fearful boy. What if the idiot had fallen in the water, or lured in by the Siren's voice? There would be no saving him then. "And where the hell are your earplugs?" Levi continued in the same angry tone.

"I don't like being called a thing." The creature interrupted before Levi could continue yelling at the boy. She sounded indignant.

"I don't care what you like or don't like." Levi's voice was cold as he spoke. He let go of Eren and turned to face the Siren. "Get the fuck out of here before I make you. I gave you lenience because you stayed away from my men. Next time I see you, I will kill you."

Levi was angry with himself as much as he was with Eren and the creature near the ship. Had the Siren killed the boy, it would have been Levi's fault for not destroying the ginger-haired female when he first saw her. He was putting his crew in danger by letting her hang around his ship. Levi moved his hand to touch the handle of his holstered pistol. The movement went unnoticed by Eren and the Siren. Levi hesitated but did not end up drawing the weapon.

The black-haired man saw the Siren still as his words sank in. Was it just him or was that an expression of hurt across her features? Levi felt a brief flash of guilt but he ignored it. Why should he feel guilt for this monster who likely murdered people? If only she didn't look and sound so human.

"Fine!" The hurt look disappeared and the Siren gave an amber-eyed glare to Levi in return. Her tail slapped the water as she dove out of sight, but not before she yelled out one final word towards the captain of the ship. "Bastard!"

A few moments later, she resurfaced. The Siren turned to Eren, pointedly ignoring a somewhat surprised Levi. He had not been expecting her to get angry or swear. Eren sighed in relief that Levi had not done anything to the ginger-haired form in the water. He found it a little amusing to see her trying to irritate Levi by ignoring him.

"Thank you for the food Eren. I'm happy someone here is not so heartless." The Siren gave Eren a small smile before turning to swim away from the ship.

"Umm, you're welcome Petra!" Eren shouted in response, to the annoyance of his Captain. Levi would make him scrub the decks for weeks for this incident. He told the boy to get back inside and help in the kitchens. Eren quickly complied.

Levi then turned back to the waters to see that the Siren was gone.

… Petra? Was that her name? Levi was almost ashamed to admit to himself that he was annoyed the Siren had never told him that.

* * *

 _Here is chapter 2! Thanks for reading! :)_


	3. Chapter 3

**Chapter 3**

Levi woke to the faint sound of wind and the gentle rocking of the ship. Laying in his bed, Levi closed his eyes once more, letting his body relax. Only ever allowing himself a few minutes to enjoy such a thing, Levi proceeded to get up. He yawned as he washed his face and dressed, leaving his cabin for the deck.

The sun had just risen, casting a red and orange glow across the water. There were a few clouds in the sky but otherwise it was clear. The gentle breeze was pleasant on his bare skin. Strangely Levi was usually up before anyone else but he heard someone else's booted feet walking along the deck that morning.

Levi was just about to head for the ship's helm when it rocked hard once and he heard the cry of one of his crew. There was a faint splash afterwards. The Captain reacted instantly. Someone had fallen in the water and, in case the Siren was back, Levi unholstered his pistol before rushing first to the left side of the ship. He leaned over the rails but found no trace of anyone. He was just about to call out when he heard a voice.

"Climb the side!" The Siren's voice stopped him in his tracks. Levi raised his gun and slowly stepped towards the voice, coming from the right side of the ship.

"Petra! I… I can't! I need someone to drop me a rope." Eren responded, his voice containing a slight tinge of panic. Levi was filled with relief that he was alive, but also wariness. The Siren was nearby, he would have to act quick if he wanted to save the boy in case she decided to attack.

The Captain moved farther down the ship before leaning over the side, allowing a bolted down rain barrel situated near the railing to keep himself hidden from sight. Both figures in the water weren't really paying attention however. He raised his gun but frowned when he saw what was before him.

The Siren was swimming along with Eren, holding him as she kept them both up with the moving ship. Levi watched as she let go or Eren to allow him the chance to try and climb up the side of the ship. He scrabbled at the wood uselessly, not able to get any grip. She took hold of him again when he failed at getting back up. Levi frowned. Why wasn't the Siren eating the boy?

"What use are your legs if you can't do something so simple?" The female growled frustratedly, holding tight of Eren as her tail rose and fell in the water.

"Simple? There's nothing to hold on to to get back up! I'm going to get in so much trouble." Eren wailed.

"You think you are? Your stupid captain's going to blame me when he sees you here." There was a tinge of panic in her voice now as well. "Well, what do we do?"

"Yell for help? I don't think I can get back up the ship myself."

"Can I get away first? I don't want anyone to slaughter me for still being here."

"Hey! Don't leave! I'm sure they won't hurt you." Eren panicked, not wanting to be left all alone in the water. He didn't think Captain Levi would hurt Petra. She hadn't done anything to anyone.

"I'm sure your captain would."

"Please don't leave Petra. What if no one comes for a while? I can't keep up with the ship forever."

"Right, sorry. I forgot you humans are not as good at swimming."

"Yeah, no pretty tails for us to help us swim." Eren agreed, laughing lightly.

"Oh! You think my tail is pretty?" The Siren's voice was filled with surprise.

"Umm, y-yeah. It's shiny like gems... or something." Eren stammered. Eloquent, Levi thought sarcastically.

"Thank you!" The Siren laughed and stopped moving to hug the now very embarrassed boy. "It's not often I get compliments. Especially from humans."

Levi saw enough and stealthily moved forward to grab a coil of rope. He tossed it over the side. Both Eren and Petra were too distracted to notice it as they had begun to swim again.

* * *

"Umm. Eren?" Petra asked as she looked at the ship again, just moments after the rope had been thrown.

"Yeah?" Eren had been about to start yelling, hoping someone would get up and save him. He was hoping it wasn't his captain.

"Is... that a rope over there?"

"What!" He looked over to where she was pointing. "Oh… It is." Had they both missed something so blatantly obvious in their panic?

Levi moved away further from the pair but watched as Petra laughed and helped Eren swim over to the rope. He wanted to make sure he was not wrong about the Siren. The boy quickly grabbed the rope and began to make his ascent.

The boy thanked Petra profusely as pulled the rope up, no doubt thinking someone must had accidentally knocked it over the side and left it like that. It was fortunate for him. Levi would never have to know what happened. He smiled at the thought. He returned to his bed, not noticing his Captain contemplating what he had just witnessed.

* * *

The Siren thought she was being sneaky but nothing on this ship passed Levi's notice. Petra thought she had successfully avoided the captain and likely believed he did not think she was still around.

Eren talked to the Siren often in the early mornings. It had been three days since he fell off the ship and Eren had always risen early to meet with Petra. Levi made sure to watch over the interactions in case the Siren tried anything but she never did. He learned more about Petra as he listened in on her and Eren's conversations.

"Hey, Petra?" Eren asked as he wiped the railing. He wanted to get an early start on his work that morning, knowing he could use it as an excuse if someone asked what he was doing.

"Yeah?"

"Uh, do you know lots of Sirens?"

"I know many but I don't talk to them much. Different tastes and all, you know."

"Right…" Eren seemed hesitant to ask what he really wanted.

"Why?"

"Would you know someone named Mikasa? Long black hair, pretty black eyes and a coal black tail. I think she would be my age by now?"

"Oh? You know, surprisingly I do. Those of us that don't share our kind's appetites tend to band together when we meet. I traveled with her for some time a year or two back. She was young but took care of herself well. How do you know her?"

"So she doesn't eat people?" Eren sighed in relief at Petra's nod. "I'm happy about that."

"Now are you going to tell me?"

"Well... I met Mikasa when I was a kid. I didn't really know what Sirens were back when I first saw her. She was screaming as she was being taken out of the water by some men. I saved her because I thought what they were doing was wrong. I leanred afterwards that she was alone and I convinced her to stay near our home when she said she had no family. I saw and talked to her every day for a year." Eren smiled at the memory but then his face darkened. "But then my parent's were killed and our house burned down. I had to leave but I promised I would find her again when I was older. It's been five years and I haven't. She's the reason I'm on this ship."

"Eren… I'll be sure to let her know you're still looking for her if I see her again."

"Thank you. I really want us to meet again."

"Aww, Eren are you in love?"

"What? No!"

"You sure?"

"We're just friends!"

"If you say so!" She laughed and dove out of sight before Eren could say anything else.

* * *

Another week passed with Eren 'secretly' meeting the Siren every morning. It would have gone on longer but Petra informed Eren that she needed to leave for a while but would be back. The boy was sad but he wished her a safe trip.

As Levi watched the feminine form swim away, he finally believed he may have been wrong about the Petra. She really did seem to be different from her kind. He was regretting his harshness towards her.

It was much later that he cursed himself for ever trusting the filthy creature and wishing he had shot her on sight.

* * *

 _Wrote this a while ago but I forgot to post it! ^.^'_


	4. Chapter 4

**Chapter 4**

It was a few days after Petra left that disaster struck.

"Captain!" One of his men called for him. He sounded nervous.

"What is it?" Levi asked, heading over with a frown. The sun was setting and cast an eerie red glow over the water.

"Its Kenny! Kenny's ship is headed right for us!" The man sounded scared.

"What?" Levi's eyes widened slightly in surprise. "What the hell does that old man want?"

Whatever it was, it wouldn't be good. Kenny was furious at Levi for leaving him and his group a few years back. The older man didn't understand that Levi never wanted to be a pirate like him. In their one encounter after Levi's departure, Kenny tried to kill him.

Levi knew there would be trouble and began to order his men to get ready for battle. Kenny's ship was faster than theirs. They could not hope to outrun him.

If it came down to it, Levi would fight. He just hoped that it would not have to come to that.

* * *

It did.

Kenny wasted no time in firing on Levi's ship. And he had a surprise for them, one that no one could have expected.

Sirens. Kenny had made some sort of deal with the Sirens. They followed his command. They emerged from the waters beside the _Wings of Freedom_ , immediately beginning to sing.

It had been too late for many of Levi's men to put in their earplugs. Those too late had jumped overboard to their deaths by the hands of those devious beasts.

The _Wings of Freedom_ was boarded and its people overpowered. Kenny had then come for Levi.

* * *

"It looks like you won't be able to escape this time, gutter rat." Kenny laughed as he leaned over the wounded captain of the _Wings of Freedom._ He ripped out the earplugs from Levi's ears. "Let this be a final lesson for you. Never betray family."

"Bastard." Levi spat as he gasped for breath, knowing Kenny wouldn't hear him. He and all his men wore earplugs and had been using signals to communicate during the battle. Kenny smirked at him and walked away, not even bothering to finish him off. He'd let the Sirens to that.

The blade in Levi's chest made it hard to breathe. It hurt, it hurt so much. He lay there, bleeding while he thought of how much he hated the man heading back for his own ship.

His men… He could hear the screams of his men as the Sirens in the water feasted. He didn't hear any more singing but that was likely because those vile creatures knew it was no longer needed. The _Wings of Freedom_ was sinking and burning.

"Levi!" The familiar voice could barely be heard over the din of screams. It was the Siren. Petra. Was she here to kill him? She had been following their ship for some time. Had she been feeding information to Kenny? Bitch.

Levi fervently wished he had killed her when he had the chance. This was her fault. She must have told Kenny where his ship was. Now she and her kin would devour them all.

"Come here!" Petra's voice sounded desperate. Levi would not though. Everyone was dead or dying. It was all her fault. If he was to be eaten, he would at least not let that one have his body. The man stayed where he was.

Levi heard singing then. He was too weak to clap his hands over his ears. The spell of Petra's voice overcame his own will. She was singing in words he could not understand. The song seemed like it was just for him, though.

Unwillingly, Levi dragged himself toward the voice. His blood soaked the wooden floor as he crawled and half dragged his body towards the sound of the voice. He _needed_ to get to her.

A small part of Levi realized something was wrong. He could not control himself. It was one of the most frightening moments in his life.

At the edge of the deck, the railing having been blasted apart, Levi tried his hardest to break free of the song's hold. But he could not. The man glimpsed amber eyes below. He closed his eyes as he pushed his body into the water below.

* * *

Levi woke with a start, hearing voices. His side hurt and he felt absolutely filthy. His eyes blinked as he realized he was on a beach. He could feel sand on his back. He was lying in the shade of a palm tree. There was laughter, both male and female. He recognized the male voice. Eren? Eren was alive?

Levi groaned as he pushed himself up. His side burned. He looked over to see that his side had been crudely bandaged with strips of fabric. How had he survived? Had he been saved before the Siren could kill him?

Clutching his side as he walked, Levi limped to the voices. He saw Eren. And Hanje. And Moblit. They were sitting on the sand, near the water.

Levi felt a wave of relief. They had survived. At least a few of his crew had survived.

Then he noticed the form in the water. All he could see was long black hair and fins. A siren? No one seemed alarmed by her presence but Levi felt a rush of blinding anger.

"Captain!" Eren noticed Levi first and rushed over.

"What happened?" Levi asked, keeping an eye on the black haired Siren.

"It was Petra! She went to find my friend for me. She's a Siren, sir. That one over there." Eren pointed to the Siren Levi had been staring at.

"When they came back to the ship, they saw that we had been attacked. They helped us, sir! We wouldn't have made it here without their help." Eren's voice wobbled. "But… It's only us. No one else made it."

Levi felt an ache in his chest. There had been so many good men and women on his ship. He also felt his anger at Petra fade.

"Where is Petra?" Levi asked. He wanted to speak to her.

* * *

After talking to the rest of his crew and eating a meal of fish and coconuts, Levi searched for Petra. He found her in a small nearby river. She was very still, floating while focused on the water. Quickly, her hand shot into the water and she pulled out a small silver fish. She popped it into her mouth before looking for another. Not knowing what to say, he just watched her instead.

He wondered why she had helped him. She was not like the other Sirens.

"Ah! Levi?" Petra's startled voice broke him from his thoughts. He found her staring at him with wide eyes.

"I just…" Levi began, a little awkwardly, "wanted to thank you. You saved us."

"I'm sorry." She whispered, which surprised him. "I'm sorry I couldn't come back sooner. There were so many that I couldn't help."

"Not your fault. Only Kenny is to blame." That bastard. He would find him and kill him.

"Are you alright? Your doctor said you would be okay after she worked on you." She swam closer to him but then hesitated. He hadn't wanted her near him before.

"I should be okay. Hanje and Moblit are experts at their jobs." Levi noticed her hesitance. On impulse, he moved forward. Petra seemed very surprised when he stepped into the water, willing to be near her without anger or suspicion. He stopped when he was almost waist deep, and close to Petra. She smiled at his show of trust. She could easily kill him, wounded as he was, had she wanted and he knew it.

"Thank you." Petra accepted the gesture. "Careful not to get the bandages wet. I've heard your skin does not like the water as much as ours."

"I will." Levi promised. "So where are we?"

"An large island about an hour's swim from your ship. Don't worry, I have some girls going for help. There are a few other humans they know."

"You've done so much for us. I don't understand why." Levi admitted.

"I wanted to help you." Petra responded a little embarrassedly. Levi left it at that, curious but noticing her discomfort. He noticed something odd about one of her fins on her elbow. It looked like part of it had ripped off.

"What happened to your fin?" Levi asked.

"Oh…" Petra lifted her arm to look at it. "Part of it broke when I was trying to drag you onto dry sand. I just pulled off the rest."

"Does it hurt?"

"No. It will grow back soon enough, so don't worry about it."

"Can I see?"

"Ah, yes." Petra swam closer and offered him her arm. Instead of just looking, he took hold of it to inspect the fin. The part of the fin that broke off looked ragged. He gently brushed it and noticed Petra flinch. So she had been lying. He didn't think there was anything he could do about it though other than let it grow back like she said. He noticed her skin, where there were no scales felt almost just like human skin. Her fin felt a little like the cartilage in his nose. He wondered what her scales would feel like.

"Do you mind…" The man didn't know how to begin, and gestured at her tail. She looked at him curiously but seemed to get it. He could see a faint bit of red form on her cheeks as she nodded.

Petra closed her eyes as she felt Levi touch the scales on her tail. It was a little embarrassing but she didn't mind. Petra had dreamed of something like this. Levi had entranced her the moment her eyes landed on him. Since then, she had followed the man, wanting to be closer to him.

Petra saw that though he was rough on the outside, he was a kind man. She had wished he would show some of that kindness to her but her kind had such a terrible reputation. She did not blame him for not trusting her. Her kind earned the hate they received by their vicious and bloodthirsty ways. He was right to not trust her and risk himself and his men.

* * *

Eren, carrying a freshly cooked fish, a coconut and a canteen of water, found Levi lying by the river later that day. He had fallen asleep under the shade of another tree, his body still exhausted from everything. Eren debated waking him up but decided to just leave the food and water nearby. He was startled when he also found Petra on the ground. He wasn't worried though. Petra had told him that she could spend up to three days on land without too much problems.

Petra was several feet away from Levi but that was a lot closer than Eren would have ever thought Levi would willingly be to a living Siren. Eren was glad to see that. He was happy to see Levi was finally beginning to trust Petra. It was not hard to see that the woman had some sort of feelings for his Captain. He didn't know what would come of that, and even if things would work out if they did.

He just hoped they would be happy. After losing so much, they all deserved a bit of happiness.

* * *

 _Trying to finish some of my older stuff so this final chapter was done rather quickly._


End file.
